多项式运算：
本程序可以实现多项式四则运算，文件夹里含源cpp文件和exe可执行文件。
经过作者多次质量检测，程序运行质量合格，满足基本的设计要求。
本程序仍存在许多可以改进和优化之处，望您加以个性化的美化！感谢您！(Polynomial operation:
Can achieve polynomial four operations, folder containing source cpp file and exe executable file.
Through the author's test, the operation quality of the program is qualified.
There are still many improvements and improvements in this program, hoping you will personalize it!)